1. Field of Invention
This invention relates to the washing and cleansing of stock carts including shopping carts with wire-rack or lattice baskets.
2. Description of the Related Art
Stock carts are generally utilized in transporting the goods intended for purchase through a store to the checkout counter and then in transporting the purchased products on to the customer's vehicle. Throughout the day, stock carts are handled by various people, carry a variety of items, and left outside until returned to the interior of the store. Each of these conditions presents an opportunity for the carts to become soiled. For example, when outside the carts can be soiled by oils and other contaminants in the parking lot, rain, snow, and animal contaminants. Human contact with the cart offers another avenue for contamination of the carts. The carts are handled by multiple customers and store personnel during the day. Each instance can result in the contamination, even unwillingly or unknowingly, with influenza or viral bacteria. Finally, contamination can occur from items are placed into the carts, particularly during the transportation of raw foodstuffs such as raw vegetables, fruits, meat, fish and poultry products, all of which may be dangerous in the uncooked form. It is not uncommon for raw foodstuffs to leak material onto the carts and onto adjacent products placed in the carts.
Contamination may be addressed by periodic cleanings. However, it is extremely labor intensive to manually clean shopping carts. Therefore, it is not economically feasible for a cart to be cleaned after each use with manual cleaning techniques. Some retailers may have a procedure for manually cleaning shopping carts but most conventional shopping carts are created with a wire-type design or plastic injection molds which are very difficult for an operator to clean manually. Even if the cart is cleaned a single time during the day by store personnel, the risk of contamination is reintroduced after the next use of the cart.
Various devices for cleaning shopping carts have been introduced in the past. Typical of the prior art are the devices embodied in the following United States patents.
Patent NumberInventor(s)Issue Date2,997,048Gertken, et al.Aug. 22, 19613,022,791LarsonFeb. 27, 19623,096,775Clarke, et al.Jul. 9, 19633,179,117Gibson, et al.Apr. 20, 19653,258,019Bellas, et al.Jun. 9, 19643,289,238Sorenson, et al.Dec. 6, 19663,444,867ThorntonMay 20, 19694,279,263PulliamJul. 21, 19814,562,848Messing, et al.Jan. 7, 19864,807,319PoitevinFeb. 28, 19896,427,707MorrisAug. 6, 2002
U.S. Pat. No. 3,444,867, entitled “Mobile Cart Washer,” issued to C. R. Thorton on May 20, 1969, discloses a portable apparatus for cleaning grocery carts. The apparatus of Thorton sprays a heated wash fluid on the carts and includes a reclamation system for reusing the wash fluid. Carts are moved through the system by a chain drive having fingers that separate nested carts to allow the carts to be cleaned individually. A bump on the exit ramp shakes excess water from the carts.
U.S. Pat. No. 4,807,319, entitled “Self Contained High Pressure Hot Water Cleaning System for Grocery Carts,” issued to Anton Poitevin on Feb. 28, 1989, discloses a portable apparatus for cleaning grocery carts. The apparatus includes a manual high-pressure pre-wash area and a wash tunnel where a cleaning fluid and a sanitizing fluid are applied to the carts. The wash tunnel includes brushes to scrub the carts and a fluid reclamation system. Carts are carried through the wash tunnel by a conveyor and dried using heated air prior to exiting the apparatus.
U.S. Pat. No. 3,022,791, entitled “Mobile Type Cleaning Unit,” issued to A. C. Larson on Feb. 20, 1962, discloses a portable apparatus for cleaning carts. The apparatus of Larson sprays a heated wash fluid and a heated rinse onto the carts and includes a reclamation system for reusing the wash fluid and another reclamation system for reusing the rinse fluid. Carts are dried using a combination of floor ribs that shake excess fluid from each cart and circulating heated air. Carts are moved through the system by a chain drive having a series of hangers that grab a cart and pull it through the apparatus.
U.S. Pat. No. 3,289,238, entitled “Mobile Automatic Steam Cleaning Unit,” issued to Dale C. Sorenson, et al., on Dec. 6, 1966, discloses a portable apparatus for steam cleaning grocery carts. The apparatus of Sorenson, et al., uses a chain drive to pull carts through a steam bath. Once steamed, the carts are ejected from the unit.
U.S. Pat. No. 6,427,707, entitled “Mobile Supermarket Trolley Washer,” issued to R. J. Morris on Aug. 6, 2002, discloses a portable apparatus for cleaning grocery carts. Carts are carried through the wash tunnel by a conveyor. Cleaning fluids are applied to the cart and an air curtain dries the carts.
U.S. Pat. No. 3,179,117, entitled “Trailer Mounted Cleaner,” issued to Rolla Robert Gibson, et al., on Apr. 20, 1965, discloses a portable apparatus for cleaning grocery carts. A heated spray of wash fluid cleans the carts. A chain drive moves carts through the system. The chain drive has lugs to separate nested carts and allow the carts to be cleaned individually. The floor includes a series of grooves and ridges to shake excess water from the carts.
Several other patents are directed to systems for cleanings mobile carts. The cleaning apparatus of U.S. Pat. No. 4,279,263 is a portable cleaning station where carts are manually cleaned on an individual basis. The cart washing apparatus of U.S. Pat. No. 3,096,775 is directed to cleaning tray carts of the type used in hospitals. The design of the tray carts is significantly different from the design of stock carts used in grocery and retail establishments, primarily in that they are closed carts. Jets spray various cleaning and sanitizing fluids over the cart. The cart is dried using an angled floor and gravity to allow excess fluid to run off. Further, carts are manually placed in and removed from the washing by chamber so no provision exists for addressing the unique problems of cleaning nestable wire carts.
U.S. Pat. Nos. 4,562,848 and 3,258,019 are directed to mobile car wash units. In the apparatus of the '019 patent, a car must be driven into a tractor-trailer and cleaning of the vehicle is performed by three workers. In the apparatus of the '848 patent, the car is carried through the wash station and moving wash arms clean the vehicle. While incorporating basic wash features such as washing and rinsing sprays with reclamation systems and drying systems, the car wash systems are not adapted to the unique problems of cleaning high volumes of nestable wire carts.